Bis[N,N-di(2-pyridylmethyl)aminomethyl] pyrazole (H L1) and 3,5-bis[N,N-bis(2-diethylaminoethyl)aminomethyl] pyrazole (H L2) formed p-pyrazolato-p-carboxylato-dimanganese( 11) complexes [Mn,L(O,CR)][BPh,], (L = L1, R = Ph; 1; L = L2, R = M e 2) and 3,5-bis[N-(2-pyridylmethyl)aminomethyl]pyrazole (HL3) gave a di(p-pyrazolato) -dimanganese(lr) complex [Mn,L3,] [BPh,], 3. The ditoluene adduct of 3 crystallizes in the triclinic space group P i with a = 14.452(3), b = 15.573(5), c = 10.988(4) A, a = 108.78(3), p = 93.31 (2) and y = 11 5.1 O(2)". X-Ray diffraction analysis revealed a di(p-pyrazolat0)-dimanganese(i1) core with M n M n separation 4.181 (2) A. Allthe complexes showed catalytic activity towards disproportionation of H202 in dimethylformamide at 0 "C. The initial rate of dioxygen evolution in the presence of 1 is first order in both the complex concentration and that of H,O,;Together with the observation of a ligand-to-metal charge-transfer band characteristic of MnlV=O in the catalysis by 2, a mechanistic scheme involving a cycle from {Mn"'(OH)), to {Mnl"(=O)}, is inferred. In the disproportionation by 3 the initial rate of evolution is first order in complex concentration and second order in that of H,O,; v = k[Mn,] [H2O2I2, k = 29 dm6 rnol-, sP).

The preparation of new dinucleating pyrazole ligands, 3,5-bis [ (2-diethylamino)ethylaminomethyl] pyrazole (H L') and 3,5-bis[ (3-dimethylamino)propylaminomethyl] pyrazole (H L2), has been accomplished. They afford binuclear copper(i1) complexes of the formula [Cu,L,] [ BPh,], (L = L1 or L2). The structure of [Cu,L1,] [BPh,], was determined by single-crystal X-ray analysis. It crystallizes in the triclinic space group P T with a = 13.437(4), b = 15.1 92(5), c = 12.364(4) A, cc = 11 6.38(3), p = 11 3.71 (3), y = 60.48(2)", and Z = 1. The complex has a bi!uclear structure doubly bridged by the pyrazolate groups with the Cu Cu separation 3.903(2) A. The configuration geometry of each copper is a square pyramid, whose basal plane is fqrmed by the two pyrazolate nitrogens and the 'articular' nitrogens [CU-N 1.906(3)-2.028(3) A] and the apical site by one of the 'terminal' nitrogens [CU-N 2.496(5) A]. The other terminal nitrogen is free from co-ordination. Cryomagnetic investigations over the temperature range 1 00-300 K revealed a strong antiferromagnetic spin exchange in both complexes. The exchange integral ( J ) based on the Heisenberg model, wasevaluated as -21 4cm-I for [Cu,L1,] [BPh,],and -181 cm-' for [Cu,L2,] [BPh,],.

N e w dinucleating ligands containing pyrazole as an endogenous bridging group, 3,5-bis-[N-(2-pyridylmethyl)carbamoyl] pyrazole ( H3L1), 3,5-bis{N-[2-(diethylamino)ethyl]carbamoyl}pyrazole ( H3L2), and 3,5-bis{N-[3-(dimethylamino)propyl]carbamoyl}pyrazole ( H3L3), and their binuclear copper(i1) complexes with azide or acetate ion as an exogenous bridge, [Cu,L(N,) (H,O),]-H,O (L = L1--L3) and [Cu,L1 (02CMe)]-2MeOH, have been obtained. Cryomagnetic investigations (5-300 K) reveal a significant antiferromagnetic spin exchange for the azide-bridged complexes ( -J = 371-297 cm-'), but a ferromagnetic spin exchange (J > +8.9 cm-l) for the acetate-bridged complex. The azide-bridged complexes are e.s.r. silent. The acetate-bridged complex is unstable in dimethylformamide (dmf) but a quickly prepared dmf frozen solution of the sample givesX-band signals characteristic of a spin-triplet ( S = 1 ) state, together with signals due to a spin doublet (S = $) attributable to monomeric copper(i1). Signals at 81 2, 1 292, and 4 380 G show a seven-line hyperfine structure (Azz = 0.01 03 cm-'); the first and third signals are assigned t o AMs = 1 transitions and the second to the AMs = 2 transition of the parallel resonance of the spintriplet state. E.s.r. simulation based on the spin Hamiltonian for the spin triplet of a dicopper(ii) system gives g , , = 2.533, D = 0.21 0 cm-l, and E = 0.020 cm-l. Only t w o components of the perpendicular resonances are recognizable at 2 11 3 and 3 81 2 G which give g, = 2.055.

SummaryThe conditions for reaction of the branched polyfluoroalkylsilane D3CL with silica gel have been examined.From elemental analyses and 29Si NMR spectra it was found that the surface coverage and endcapping of D3CL-coated silica gel (Fluofix | were the same as for ODS packings.The separation behavior of these phases was compared that of a variety of other packings. For polyaromatic compounds and benzene derivatives Fluofix worked in the reversed-phase mode and its retention characteristics were similar to those of C 1 or CN packings. For fluorinated compound the retention characteristics of the phases is similar to those of ODS although with MeOH-water and MeCN-water mobile phases the pressure loss was lower for the fluorinated phases than for ODS.

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